2012 Constitución earthquake
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  | |
| UTC time | 2012-03-25 22:37:06 |
|---|---|
| ISC event | 600841739 |
| USGS-ANSS | ComCat |
| Local date | 25 March 2012 |
| Local time | 19:37 (UTC-4) |
| Magnitude | 7.1 Mw |
| Depth | 40.7 km (25.3 mi) |
| Epicenter | 35°12′00″S 72°13′01″W / 35.200°S 72.217°W |
| Type | Thrust[1] |
| Areas affected | Chile |
| Max. intensity | MMI VIII (Severe) |
| Casualties | 1 dead |
The 2012 Constitución earthquake was recorded on March 25, 2012, at 7:37 pm local time. It had a moment magnitude of 7.1 and its epicenter was located 23 km (14 mi) northeast of the city of Constitución, in the Maule Region, Chile.[1] According to experts, it was a strong and late aftershock of the Great Chile earthquake of February 27, 2010.
The earthquake was felt from Coquimbo to the Los Lagos Region, with the Maule Region being the most affected and causing high commotion in the O'Higgins and Bio-bío regions, which were affected by the earthquake of 2010.
The earthquake occurred as the result of shallow thrust faulting on or near the subduction interface between the Nazca and South American plates. At the location of this event, the Nazca plate moves east-northeast relative to South America at a velocity of about 74 mm/yr.[2] The Nazca plate, oceanic in origin, subducts eastward beneath the South American plate at a shallow angle from the Peru-Chile Trench. It is seismically active to depths of approximately 200 km (124 mi) adjacent to the epicenter of the March 25th earthquake, though farther north seismicity continues to depths exceeding 600 km (370 mi).
In historical times the Chilean coast has suffered many megathrust earthquakes along this plate boundary, including the strongest earthquake ever measured, which is the 1960 Valdivia earthquake.[3] More recently, the boundary ruptured during the 2015 Illapel earthquake in northern Chile.[4]
Earthquake
| Modified Mercalli intensities in selected locations[1] | ||
| MMI | Locations | |
|---|---|---|
| MMI VIII (Severe) | Cauquenes Constitución Pelluhue Talca | |
| MMI VII (Very strong) | Cobquecura Parral Pelarco Villa Alegre | |
| MMI VI (Strong) | Curicó San Clemente | |
| MMI V (Moderate) | Rancagua Chillán | |
| MMI IV (Light) | Santiago Valparaíso Mendoza | |
| MMI III (Weak) | Buenos Aires San Juan | |
The earthquake occurred at 19:37 local time, having a maximum Mercalli intensity of VIII (Severe).[1] The earthquake was felt in the Chilean capital Santiago with an MMI intensity of IV (Light).[1] It was said to be an aftershock of the 2010 Chile earthquake.[1]